Method and apparatus for reconditioning cylinder liners for diesel engines



2,912,562 METHOD AND APPARATUS FOR RECONDITIONING CYLINDER LINERS FORDIESEL ENGINES Filed April 22, 1957 Nov. 10, 1959 G. c. DONOVAN 2Sheets-Sheet 1 65am: cDa/mm/Y INVENTOR.

Nov. 10, 1959 s. c. DONOVAN 2,912,562 METHOD AND APPARATUS FORRECONDITIONING CYLINDER LINERS FOR DIESEL ENGINES 2 Sheets-Sheet 2 FiledApril 22, 1957 FIG. 2

90 6'50: (7 Da/ram/r mmvnm H7" TOEME V of standard cylinder liners formounting the liner during United States Patent METHOD AND APPARATUS FORRECONDITION- ING CYLINDER LINERS FOR DIESEL ENGINES This inventionrelates to methods and apparatus for reconditioning the inner surface ofcast iron cylinder liners used in engines, particularly diesel engines.

All diesels used in railroad locomotives have liners in the cylinders,and heretofore when a liner became worn and could no longer be reboredit was removed and replaced with a liner of correct dimensions. Owing tothe rather intricate design of these cast iron liners, the replacementcost is high. Consequently there is a need for an inexpensivereconditioning procedure.

One object of the instant invention is to provide a simple method andapparatus whereby the inner surface of a worn cylinder liner may beeffectively reconditioned at a cost substantially less than thepurchase-price of a new liner.

7 Another object of the'invention is to resurface the inner wall of acylinder liner in such a manner that the liner will not becomedistorted. In this regard it will be appreciated that thereconditioned'liner must fit back .into the engine block withoutinterference and that the liners bore when reconditioned must be capableof being. machined to accommodate properly the reciprocable pistontherein. More specifically, the invention contemplates and it is anobject to provide methods and apparatus for depositing of weld metaloverthe entire inner surface of a cylinder liner by electric arc weldingand to use the integral water jacket circumscribing the major portion ofthe liner structure for supplying cooling water to the liner during thewelding period. Since the integral jacket does not extend all the way toone end of the liner structure it is a further object of the inventionto provide means for assuring that a flow of water is directed againstthe reverse side of every portion of the liner wall upon which weldmetal is deposited.

Still another object of the invention is to permit the utilization ofthe threaded studs projecting from one end reconditioning. When theliner is actually installed in use these same studs extend upwardlythrough the cylinder head.

Other and further objects are those inherent in the invention and willbe apparent as the description proceeds.

To the accomplishment of the foregoing and related ends, this inventionthen comprises the features hereinafter fully described and particularlypointed out in the claims, the following description setting forth indetail certain illustrative embodiments of the invention, these beingindicative, however, of but a few of the various ways in which theprinciples of the invention may be employed.

In the drawing:

Figure 1 is a perspective view of apparatus utilized in the practicingof my reconditioning method;

Figure 2 is a sectional view taken in the direction of line 22 of Figurel;

being in the direction of line 3-3 of Figure 2; and

Figure 4 is a modified embodiment of my invention showing the cylinderand the members in immediate proximity in section and an automatic setupfor welding, part of the latter being shown in schematic.

Referring now in detail to Figures 1 and 2 of the drawing, theconstruction of a typical cast iron cylinder liner 10 for locomotivediesel engines will first be described. From Figure 2 it will be notedthat the liner 10 is of what will be termed generally a double wallstructure having an inner wall 12 and an outer jacket 14 forming achamber 16 therebetween through which the cooling water flows. It is, ofcourse, the inner surface 18 thataccommodates one of the diesels pistonswhen the liner 1t isinstalled in an engine block. Intermediate the endsof the liner 10 is a plurality of radially directed exhaust ports 20 toadmit scavenging air for compression. I

Further describing the conventional liner 10, it will be observed thatthe left end 23 of the liner as it appears in Figure 2 is provided witha water port 24, actually one of a plurality of such ports leading tothe chamber 16. Later on it will be seen that for purposes ofillustration seven such ports will be referred to since this is thenumber in a certain cylinder sleeve. When installed in an engine blockthese ports 24 serve as discharge ports from the chamber lti, but duringa reconditioning operation they will function to admit water to saidchamber, all in a manner hereinafter explained. Angularly disposedbetween each pair of ports 24 is a threaded stud member 26 which is apart of the liner assembly. Special use of these studs 26 will" be madefor rotatably mounting the liner 10 during its repair. Normally, though,these studs extend upwardly through the cylinder head of the dieselengine. In both situations a nut 28 is affixed to their projecting ends,their oppositeends being threadedly received in tapped apertures formedin the liner structure. 7

Close inspection of Figure 2 will reveal that the jacket 14 and hencethe chamber 16 do not extend completely to the other end 30 of the wall12. Instead the jacket 14 terminates short of the end 30. A series ofports 32, in practice, function to admit water from a manifold part ofthe engine, in which the lower end of the liner 10 is positioned.Consequently, while practically the entire length of the inner wall 12is cooled in actual operation, a problem of cooling this extended wallportion exists as far as reconditioning is concerned. More will be saidpresently as to how complete cooling is derived during repair.

The foregoing discussion completes the description of a conventionalcylinder liner. 'At this time specific attention is drawn to Figure 1where the apparatus utilized in carrying out a reconditioning operationof the cylinder liner 10 is pictured. In this figure there is shown aportion of a lathe generally designated 36. A pair of bearing pedestals38 journal a hollow spindle 40, passage 42 extending completelytherethrough as shown in Figure 2. A water swivel 44 is connected to thespindle and coupled to a fixed pipe 46 having a valve 48 therein bywhich water from a supply is furnished to the spindle while it isrotating. The spindle is rotated by pulley 50 and belt 52 driven by amotor, not shown.

Threaded onto the end of the spindle 40 opposite the swivel 44 is aspecial face plate 54 having a centralwater port 56 and a series of boltholes 58 corresponding in number to the number of studs 26 on theparticular cylinder sleeve being reconditioned. In thesleeve hereillustrated there are seven studs. plate 54 and the end 23 of thecylinder liner 10 is a special manifold plate 60 having a plurality ofradially arranged grooves 62 leading from a center which is overIntermediate the face 1 shown) port 56, thence outwardly to a similarnumber of water ports 64. The water ports 64 are intended to be alignedwith the previously mentioned ports 24 and hence are of the same number,here seven. Between each adjacent pair of water ports 64is an additionalhole 66, to accommodate studs 26. A gasket is provided at 60A and onemay be provided between the plates 54 and 60 if needed.

From the preceding description it is believed obvious that cooling watermay flow in controlled volume through the valve 48, pipe 46, swivel 44,and spindle 40, then from the spindle through the central aperture 56 ofthe face plate 54, thence via the radial slots 62 of the manifold plate60 to the apertures 64 where the water is delivered into the chamber 16.

Since the cooling water utilized during my process exits via the ports32, to cool the entire inner wall 12 including that section to the'right of the ports 32 as shownin Figure 2, the invention contemplatesthe provision of an adapter sleeve designated 70. The sleeve 70 -issubstantially the same diameter as the jacket 14, it being intended thatit either abut thereagainst as shown in Figure 2 or circumscribe aportion thereof to form an auxiliary chamber 72 in series with thejacket chamber 16.

The sleeve 70 is equipped with an integral inturned flange 74 whichseats on the end 30 of the liner 10. Neither the sleeve 70 or itsannular flange 74 need be of heavy gauge stock and therefore the flange74 is capable of flexing somewhat, if such proves necessary. A gasket.may be used if desired. A series of circumferentially spaced smallaperture 76 allow the water to be disends 82 and opposite threaded ends84. The hook ends 82 reach into the ports 20, whereas the ends 84 extendthrough lugs 86 on the sleeve 70. Nuts 88 on threaded ends 84 permit thestay to be pulled tight and the stays thereby collectively hold thesleeve 70 in its telescoping position with respect to the end of theliner 10.

In the exemplified situation use is made of the lathe carriage 90 forholding and manually feeding a welding electrode 92 having a nickel ornickel-alloy core 94 and a suitable flux coating 96. It is this weldingelectrode 92 that is to be utilized in depositing a layer of weld metal100 on the inner surface 18 of the cast iron liner 10. As isconventional with the lathe carriages, the carriage 90 may be manuallymoved longitudinally of the lathe 36 by ,means of a lead wheel 102 or ifdesired an automatic travel may be effected by means of the lead screw(not The carriage 90 supports a cross slide 104and by reason of a crossfeed handle 106 the slide 104 may -be manually or automatically advancedtransversely of ,the lathe to compensate for consumption of the weldingelectrode 96.

A modified tool post 108 is employed for holding the welding electrode96 inasmuch as it is of stacked construction, there being an insulatingwasher 110 so as to electrically isolate the upper end thereof. Theactual clamping of the electrode 96 to the upper metallic portion of thepost 108 is through the agency of a thumb screw,

112, the lower end of the screw contacting the core 94.

The simplest manner of proceeding according to my invention is to carryout the method manually using the setup shown in Figures 1 and 2. InFigure 4 there is illustrated an automatic setup.

In either the manual or automatic setup the welding circuit includes aDC. generator 114 having an armature 116, shunt field coils 118,commutating coils 120 and series field coils 122. A current range switch124 permits selection of the approximate value of welding current to beemployed, whereas a current adjusting rheostat 126 permits a fineradjustment within the broade f Iange. A

polarity reversing switch 128 is also included in the i1- lustratedcircuitry, it being preferable that reverse polarity be used because ofthe cast iron construction of the liner 10. A conductor 130 leadsdirectly to the upper end of the post 108. The other side of the switch128 is grounded at 132, the grounding of the lathe 36 at 134 completingthe electrical circuit via the welding electrode 92 when the switch 128is closed and an arc is struck.

Having in mind the construction and arrangement of the principalelements thereof, it is believed that a com plete understanding of boththe apparatus and method constituting my invention may now be had from adescription of the operation. First, the valve 48 is opened to admitcooling water to the chambers 16 and 72. Then the spindle 40 is rotatedby energizing the motor (not shown) which drives the belt 52. With thecast iron liner 10 rotating, the welding is'started with the weldingelectrode 92. Before actually striking an are one should be sure thatthe current range switch 124 has been placed in a low position and thatthe rheostat 126 has been adjusted for a relatively low value of weldingcurrent. The precise value of welding current will depend upon size ofrod 92 and upon the quantity and temperature of cooling water passingthrough the chambers 16 and 72 together with the specific thickness ofthe inner wall 12. I prefer to use a small rod, say A" or less and touse the minimum current for holding the arc. Solely as a guide, and notwith any thought of limiting the invention, for a electrode the currentwill be in the neighborhood of 55-65 amperes. As hereinbefore indicatedthe electrode 92has a nickel or nickel-alloy core. With the abovepreliminary arrangements completed the actual surfacing operation can beundertaken. Assuming that the carriage 90 has been initially movedfarther to the left than it now appears in Figure 1 and that arelatively long welding electrode 92 is used, an arc is struck at theleft end of the liner 10. This is readily accomplished by advancing theslide 104 toward the far side of the lathe and then retracting some.Thereafter the carriage 90 is gradually moved toward the right until thefirst electrode becomes spent, that is too short to continue. Then asecond electrode is substituted and so on until the entire inner surface18 has been covered with what amounts to a weld deposit in the form of ahelical, slightly overlapping bead. Figure 1 shows the liner nearing itscompletely reconditioned stage asfar as the depositing of weld metal isconcerned. The are is interrupted at ports 20, or if desired carbonplugs may be inserted in the ports 20 to carry the arc across.

Upon full completion, the liner 10 may be removed from the face plate 54and rebored on a different lathe or the same lathe 36 may be used formachining the interior of the inner Wall 12 to its original diameter.

While a flux coated welding electrode has been described, it will beappreciated that the electrode may constitute a nickel-iron wire andthat an inert gas may be introduced into the interior of the linerthrough the annular flange to prevent undue oxidation. According to myinvention an automatic electrode feeder for wire electrodes, may bemounted on the tool post 108. The electrode wire is then fedautomatically. The amount of 'metal deposited and the overlap ofsuccessive heads is determined by varying the rate of feed of the lathecarriage 90. In the case of automatic feed the position of rod 92illustrates the position of the guide for the wire electrode. Also theflange 74 maybe extended so as to nearly close the end of the cylinderto keep in the shielding gas such as helium-argon. Thus overlapping beadis deposited spirally and this may be with a small wire and are tominimize local heating.

In Figure 4 the setup for holding the cylinder is similar to that shownin Figures 1 and 2 except that plate 60 is made slightly larger so boltsA can be run back through it for securing the temporary sleeve 70 inplace. Water is run through as previously described. It is noted, withreference to Figures 1, 2 and 4 that the ports 76 are made small inorder to insure a little pressure in the jacketing. In this way one canbe certain all surfaces being welded will be backed up with water. Alsoin Figure 4, carbon plugs are fitted into ports 20, flush with theinside. As the weld bead is being laid, the are travels across thecarbon plug, but the bead metal is' not secure on the carbon and iseasily cleaned out with the carbon plug, when the job is finished.

In Figure 4, the lathe cross head 104 is used to mount the bracket 11%)upon which there is carried an automatic arc welding electrode wirefeeder head 112. The feeder head 112, per se, is not a part of theinvention, and a standard feeder head may be used for feeding theelectrode wire automatically according to the are voltage or at aconstant rate. The electrical are power system is accommodated to theparticular feeder head used. The feeder head 112 may include its own,internal supply for a shielding gas (argon-helium etc.) but if not, thegas (where used) is supplied externally via pipe 116 which is supportedby post 115 from bracket 110. Gas is supplied via port 116. Theelectrode wire guide'sleeve 117 slips loosely through gas tube 114 andthe electrode wire 120 slides through tube 117, being fed automaticallyfrom the feeder head 112, also on bracket 110.

The two concentric tubes 117 and 114 and the electrode wire 120 slantdownwardly into the sleeve 10 being reconditioned. The rotation ofspindle 40 of the lathe and the rate of feed of carriage 90 are adjustedin relation to the rate of deposition of weld metal so that thesuccessive turns of the weld bead 100 (which is laid on spirally), willoverlap just a little.

The wire electrode 120 can be carried on spool 112A and the arc weldingcurrent conducted through a brush connection to the active end of theelectrode wire or may be conducted through the wire on the spool to theextending end being fed to the arc. Control of voltage in the arccircuit to compensate for the wire fed is done as required, to keep thevoltage at the are within desired limits. The cylinder sleeve is, ofcourse, grounded through the lathe as shown diagrammatically in thedrawings. A slip ring connection (not shown) may be made to the lathespindle 44), if needed, but this is not usually needed because thesleeve bearings of the lathe will usually conduct the relatively lowwelding current used. Use of graphite grease in the spindle bearingsassists conduction.

In order to retain the are shielding gas within the cylinder sleeve, andreduce wastage as much as possible, I provide two plates 121 and 122.Plate 121 is mounted stationary on the lathe bed so as to lie flat andvertical against flange 74 of the temporary jacketing sleeve 70 whichsimply turns with its end in flat contact with the plate 121. There needbe no great pressure, merely a The plate 121 has a vertical slot 121A init which is wide enough and high enough to accommodate movement of thetube M4 for as the carriage 90 moves along the lathe bed the tube 114(and 117) will be withdrawn and hence the elevation at which tube 117crosses the plate 121 will gradually decrease. In order to close theslot 121A, I provide the plate 122 which has a hole 12 2A in it throughwhich tubes 114- 117 pass loosely. Plate 122 simply hangs on the tube117 and slides down the tube until it is in flat contact against plate121. Hence as the tubes 14-117 are withdrawn the plate 122 graduallyslides down the tubes 114-117, always meanwhile resting against plate121 and hence covers slot 121A. The are shielding gas which flows intothe liner via tubes 1 1 6 and 114 thus fills the interior of the liner10 and provides an atmosphere of such shielding gas within the liner 10and much less gas is required as when the are shielding gas is usedunder open conditions. There need be only a slight flow of such gaswhich first flushes the air out of the liner 10 and then itself leaksout between flange 74 and plate 121 and between plates 121 and 122 andaround tube 114 where it passes through hole 122A. The leakage outflowcarries away some are heat, but principal reliance for cooling the liner10 is placed upon my method of backing up the entire surface which is tobe welded by means of water which is kept flowing briskly against theouter surface of the sleeve tokeep the entire sleeve cool. Arc heat isaccordingly localized at the arc and the heat is drained away as fast asit is evolved by the are.

As many widely apparently diflerent embodiments of this invention may bemade without departing from the spirit and scope thereof, it is to beunderstood that I do not limit myself to the specific embodimentsherein.

What I claim is:

l. A method of reconditioning the inner surface of a cast iron cylinderliner having an outer water jacket concentric to' its longitudinal axiscomprising the steps of mounting said liner to have its longitudinalaxis extend through a nearly horizontal plane passing a cooling fluidthrough the jacket of said liner, rotating said liner about itslongitudinal axis while said cooling fluid is passing through saidjacket, and simultaneously depositing a layer of weld metal on saidinner surface.

2. A method in accordance with claim 1 in which the depositing step iseifected by means of electric arc welding.

3. A method in accordance with claim 2 in which said arc welding step isaccomplished with an electrode containing nickel.

4. A method in accordance with claim 3 including the additional step oflimiting the arc current to a value such that overheating of thecylinder liner is prevented for a given flow of cooling fluid.

5. A method of reconditioning the inner surface of a cast iron cylinderliner having an outer water jacket comprising the steps of passing waterthrough the jacket of said liner, rotating said liner about itslongitudinal axis while said cooling water is passing through saidjacket, traversing a nickel containing welding electrode from one end ofthe liner to the other to deposit a helical bead of weld metal on saidinner surface and controlling the electric current flowing through saidwelding electrode so that overheating of the cylinder liner .isprevented for a given flow of cooling water.

6. Apparatus for reconditioning the inner surface of a cast ironcylinder liner having an outer water jacket comprising means forrotating said liner about its longitudinal axis and holding said linerto have its longitudinal axis extend in a generally horizontal plane,means for passing a cooling fluid through the jacket of said liner tocontact the outer surface of the liner while said liner is beingrotated, and means for simultaneously depositing a layer of weld metalon said inner surface.

7. Apparatus for reconditioning the inner surface of a cast ironcylinder liner having an outer water jacket comprising means forrotating said liner about its longitudinal axis, means for passing acooling fluid through the jacket of said liner while said liner is beingrotated, said means for passing a cooling fluid including a face platehaving a channel therein whereby the cooling fluid maybe conducted fromthe means for rotating said liner about its longitudinal axis to theouter water jacket, and means for simultaneously depositing a layer ofweld metal on said inner surface, the last mentioned means including aholder for a welding electrode.

8. Apparatus in accordance with claim 7 in which said last mentionedmeans includes a carriage mounted for longitudinal and transversemovement relative to said rotating means, said carriage supporting saidholder.

9. Apparatus accordance with claim 7 including means for adjusting thevalue of the electric current flowing through said electrode and meansfor adjusting the flow of cooling fluid through said jacket.

10. Apparatus for reconditioning the inner surface of a cast ironcylinder liner having an outer water jacket extending from one endthereof toward its opposite end but terminating at a locus spaced fromsaid opposite end, a face plate having a central aperture and aplurality of angularly spaced .apertures disposed radially outward fromsaid central aperture, means for rotating said face plate, conduit meansfor supplying cooling water through said central aperture, means forattaching said cylinder liner relative to said face plate for rotationin unison therewith, manifold means for distributing the cooling watersupplied via said central aperture to one end of said jacket, a wateradapter sleeve having an inturned flange at one end engageable with saidopposite end of said cylinder liner, the other end of said adaptersleeve being engageable with a portion of said cylinder liner adjacentthe nearer end of said jacket, and welding electrode holding meansmovable longitudinally and transversely of said face plate fortraversing said electrode within the cylinder liner to deposit a layerof weld metal on the inner surface thereof. a

11. Apparatus in accordance with claim in which said adapter sleeve isformed with a plurality of radially directed apertures adjacent itsinturned flange for the discharge of said cooling water.

12. Apparatus in accordance with claim 11 in which said cylinder lineris provided with a plurality of scavenging ports directed inwardlythrough the jacket intermedially the ends thereof, said adapter sleevehaving a plurality of radially projecting lugs thereon, and a pluralityof stay members having offset portions at one end engageable in saidports andhaving their other ends adapted to engage said lugs to therebyretain said adapter sleeve on said cylinder liner.

13. Method of reconditioning a cast iron cylinder liner for an internalcombustion engine which comprises mounting said cylinder sleeve forrotation about its longitudinal axis, forming a water jacket around saidsleeve to have a longitudinal length approximately equal to the lengthof the sleeve and passing a flow of water continuously through saidjacket for cooling the outer surface of the sleeve continuously duringreconditioning, depositing a continuous spiral of weld metal in a beadin which successive turns of the spiral overlap at least slightly whilesaid sleeve is continuously cooled by a flow of water passing throughsaid jacket.

14. The method of claim 13 further characterized by closing both sleeveends sufficiently to retain an atmosphere of non-oxidizingarc-stabilizing gas in the interior of said sleeve, and introducing awire of arc electrode metal through the said closure into closely spacedrelationship to the interior surface of said sleeve for forming an arcfor depositing the said metal on the interior surface of said sleevewhile introducing said gas thereinto.

15. The method of claim 14 further characterized in that the gas isintroduced into the sleeve through the same end of the liner as thewire, the outflow of gas from said sleeve is restrained, and acontinuous flow of such gas into the sleeve maintained while metal fromsaid wire is spirally deposited in an overlapping spiral on the interiorof said sleeve.

16. An apparatus for reconditioning cast iron cylinder sleeves ofinternal combustion engines which comprises means for mounting saidsleeve for rotation about the axis of said sleeve, water jacket meansaround the exfor conducting a flow of water continuously through said '8sleeve but out of contact with the interior surface of said sleeve,means for closing the ends of said sleeve sufficiently to restrain theoutflow of gas from the in: terior of said sleeve, means for introducinga flow of non-oxidizing arc-stabilizing gas into the interior of saidsleeve, means for introducing a continuous welding wire electrode intosaid sleeve and into proximity with the ends thereof, and for movingsaid electrode longitudinally of the sleeve as the sleeve is rotated,means for introducing a flow of electric current through said electrodeand through said are and said sleeve for maintaining an are between theelectrode and the sleeve as the sleeve is rotated, means for moving theelectrode longitudinally of the sleeve for depositing a spiral head ofweld metal on the interior thereof as the sleeve is rotated thesuccessive turns of said spiral overlapping at least slightly forbuilding a continuous layer of weld metal on the interior of saidsleeve. i

17. Apparatus for lining a cylinder made of ferrous material havingawater jacket about the surface of said cylinder opposite the one to belined, means for rotating said cylinder, means to conduct water throughthe aforementioned means to the water jacket without obstructing thesurface that is to be lined, means for making a positive connectionbetween the cylinder and the rotating means and electric arc weldingmeans for depositing a lining on the cylinder while it is rotated.

18. The apparatus of claim 17 further characterized in that there isprovided means for retaining an atmosphere of non-oxidizingarc-stabilizing gas in the presence of the surface of the cylinder beinglined, said means being mounted outside of the cylinder in spacedrelation thereto.

19. A method of reconditioning the inner surface of a cast iron cylinderliner having an outer concentric water jacket of a substantially shorterlength than the length of the jacket to be lined comprising the steps ofextending the effective length of the water jacket to be substantiallyequal to the length of the liner to be reconditioned, passing a coolingfluid through the water jacket in contact with the outer surface of thelength of the liner to be reconditioned, rotating said liner about itslongitudinal axis while said cooling fluid is passing through saidjacket, and simultaneously depositing a layer of weld metal on saidinner surface.

20. Apparatus for reconditioning the inner surface of a cast ironcylinder liner having a concentric outer water jacket of a longitudinallength substantially shorter than the longitudinal length of the linerto be reconditioned comprising means for extending the effective lengthof the water jacket to be substantially equal to the longitudinal lengthof the liner to be reconditioned, means for rotating said liner aboutits longitudinal axis, means for passing a cooling fluid through thejacket of said liner while said liner is being rotated, and means forsimultaneously depositing a layer of weld metal on said inner surface.

References Cited in the file of this patent UNITED STATES PATENTS1,886,503 Shockey Nov. 8, 1932 1,898,060 Noble Feb. 21, 1933 1,924,876Morgan Aug. 29, 1933 2,187,786 Jacobus Jan. 23, 1940 2,496,188 WieseJan. 31, 1950 2,654,014 Schaefer Sept. 29, 1953 2,729,578 Hedlund et a1..Tan. 3, 1956

